More than two weeks after an airstrike on a migrant detention centre in Libya's capital left at least 53 people dead and many more wounded, the UN said that more migrants and refugees are being brought to the Tripoli facility, despite ongoing fighting.

The UN's International Organisation for Migration (IOM) said in a tweet on Monday that "a new group of migrants" had been taken to the detention centre, Tajoura, adding that the agency "reiterates that migrants' safety must be guaranteed".

According to media reports, some 200 people were being held in Tajoura as of Tuesday even though migrants, refugees, and asylum seekers who survived the deadly 2 July strike were released last week. The UN said the strike could constitute a war crime.

Amidst a growing chorus of appeals to free the approximately 6,000 people known to be held in Libya's detention centres - long cited for their desperate conditions - aid groups are struggling to support current and former detainees as three-and-a-half months of clashes in and around Tripoli continue, despite calls for de-escalation.

Rights groups say the Libyan government should share responsibility for the poor conditions, as should EU member states, whose efforts to curb migration - including support for the Libyan Coast Guard and allegedly paying off militias involved in smuggling - have left vulnerable people trapped in Libya with no way out.

With limited options for resettlement outside the country and boats intercepted in the Mediterranean still being sent back to Libya, here's what we know about the current situation for migrant detainees, what sort of help they are getting, and their prospects for release.

Will Libya's migrant detention centres be closed?

The UN-backed Government of National Accord (GNA) said on 4 July that it was considering the closure of all of Libya's migrant detention centres, which hold roughly 6,000 individuals - most from sub-Saharan Africa - in dozens of facilities across the country.

But while Tajoura is run by a militia aligned with the GNA, which has been fighting eastern forces loyal to general Khalifa Haftar's Libyan National Army (LNA) for control of the capital city since late April, the UN-backed government does not control all of Libya, nor does it run all of the country's detention centres.

A European Union spokesperson called last week's release of the original Tajoura detainees a "positive step" and said "all refugees and migrants have to be released from detention and provided with all the necessary assistance".

But shortly after that, 90 people attempting to leave Libya were intercepted at sea by the EU-trained and equipped Libyan Coast Guard, and sent to Tajoura.

Other migrant groups - some rounded up from the local community, others relocated from other detention centres - have also been sent to the centre in recent days, creating the "risk of another tragedy" given the ongoing clashes, said IOM and Charlie Yaxley, a spokesman for UNHCR, the UN's refugee agency.

Who is responsible for the Tajoura airstrike?

The UN has called for an independent investigation to establish responsibility for the attack, but many suspect it to be the work of Haftar's forces, which have been conducting air raids against GNA targets in the vicinity of Tajoura.

The Tajoura facility, which held more than 600 mainly African migrants and refugees, was situated in a military compound controlled by a pro-GNA militia. A New York Times investigation showed a weapons depot some 90 metres from where the detainees were living.

Media reports suggest there were two strikes; one hitting the weapons depot, a second hitting the detainees' living quarters. The UN said the coordinates of the detention centre - and others in Tripoli - were known to combatants.

The same weapons depot was previously hit on 7 May, injuring two detainees. The UN called for the occupants to be moved but nothing was done. On 23 April, LNA-aligned fighters reportedly opened fire on detainees in the Qasr Bin Ghashir detention centre south of Tripoli, killing several people.

Who is getting aid to the detention centres?

A mixture of international and local NGOs supply aid to detainees, but access is "subject to the daily whims" of militias that control many detention centres, said one aid worker in Libya who asked not to be named due to the sensitivity of the matter.

Getting help where it needs to go has become more challenging since the late April uptick in fighting due to daily clashes and the difficulty of negotiating with militias. Companies contracted by the Libyan authorities to provide food to detention centres have been forced to cease deliveries due to ongoing fighting.

Kasper Engborg, deputy head of the UN's emergency aid coordination body in Libya, OCHA, said support for detainees is provided on an "ad hoc basis" so as to avoid aid groups inadvertently propping up the detention centres and legitimising a "situation that we don't agree to".

He added: "We do not believe that detention centres should exist."

How has the conflict impacted people in detention centres?

Nearly 3,400 individuals are trapped in ten detention centres near the fighting in and around Tripoli, according to the UN - although these figures have not been updated since the Tajoura releases and new detentions.

Some detainees say they have been forcibly conscripted to fight or clean arms; others have been wounded or killed in airstrikes and ground attacks.

Aid groups say access to the detention centres - some of which are controlled by militias - has become increasingly difficult since the fighting began, with detainees forced to live in unsanitary conditions without food, water, and basic medical supplies.

Migrants and refugees have long faced a litany of abuses inside centres, where disease is rife, and rapes, beatings, kidnappings, and extortion have been reported. Many are in Libya as way-station to Europe, where they hope to escape war and persecution, while others are seeking new economic opportunities.

Conditions in the detention centres have deteriorated further since fresh conflict engulfed the capital in April, when forces loyal to Haftar began a march on Tripoli.

Deaths inside detention centres are not limited to armed conflict. A lack of medical services means detainees regularly succumb to preventable illness like tuberculosis, which the medical charity Medecins Sans Frontières (MSF) says likely caused at least 22 fatalities in two detention centres between September and May this year.

What happens to detainees who are released?

UNHCR has been advocating for the "immediate release of refugees and migrants from places of detention," but aid groups also say they have little capacity to assist detainees once they leave the centres.

After the Tajoura airstrike, UNHCR attempted to relocate the 55 "most vulnerable refugees"; hundreds of others were filmed walking the streets of Tripoli, their belongings in plastic bin bags.

Most of the former detainees are now sheltering in UNHCR's "Gathering and Departure Facility" (GDF), which is intended to host individuals who have been declared eligible for refugee status and are awaiting resettlement.

Engborg of OCHA said the former Tajoura detainees will be asked to leave the "badly overcrowded" GDF facility in the coming days and find their own accommodation, which is the case for the estimated 600,000 migrants, refugees, and asylum seekers currently living in Libya.

Former detainees - along with those already living on their own - may be "at risk of exploitation and abuse from people smugglers and traffickers," said Elinor Raikes, Europe and North Africa director at the International Rescue Committee.

Sam Turner, MSF's head of mission in Libya, said it wasn't clear what the humanitarian community would do if all the country's detention centres were shut:"We don't have a contingency plan in place to cope with the release of people from detention," he said.

Two of three community day centres intended to support migrants and refugees in urban communities have been forced to close in recent weeks due to ongoing clashes, said UNHCR's spokeswoman in Libya, Paula Barrachina. The remaining facility receives 150 people per day, Barrachina said, and is "at full capacity".

"Resources have to be increased to be able to respond to all persons in need," she added.

Since April, UNHCR has relocated hundreds of individuals from detention facilities near front lines, such as Qasr Bin Ghashir. They have mostly been transferred to other detention centres in safer locations, and a number have been moved to the GDF facility.

UN officials are now discussing proposals with the GNA for former detainees to be housed in new "open" shelters, where they can come and go freely, said Engborg.

But efforts to establish such centres may take time and will be complicated by the ongoing conflict.

How many refugees have been resettled since the violence began?

UNHCR has evacuated 589 refugees to safe third countries since April, including 295 to Italy and 294 to Niger - where refugees make a supposedly temporary stop before being resettled in Europe.

So far this year, nearly 1,300 people have been evacuated from Libya, but roughly three times that number have been intercepted at sea by the Libyan Coast Guard and brought back to detention centres. This means that the "cycle of human misery and danger is just perpetuated," said the International Rescue Committee's Raikes.

The UN has appealed for more countries to offer resettlement spots, and Germany's development minister, Gerd Müller, called for a "joint humanitarian initiative" from Europe and the UN to rescue refugees on Libyan soil.

But there remains a lack "of sufficient resettlement spaces through the pledges that have been announced by different governments around the world," MSF's Turner said.

IOM runs a voluntary repatriation programme that supports individuals who decide to return home. Many of those affected by the Tajoura airstrike were already registered on the programme, the agency said.

A total of 5,089 individuals have returned to 26 countries across Africa and Asia so far in 2019 as part of the IOM programme. But the decision to return home is not for everyone, given the hardship and financial costs most incur in their journey to reach Europe.